<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<select onchange="change()" multiple>
		  <option class="aaa" value ="volvo" selected="">Volvo</option>
		  <option class="aaa" value ="saab">Saab</option>
		  <option class="aaa" value="opel">Opel</option>
		  <option class="aaa" value="audi">Audi</option>
		</select>
	</body>
</html>
<script src="js/jquery-3.2.0.js" type="text/javascript" charset="utf-8"></script>
<script type="text/javascript">
	function change($event){
		// console.log($event);
	}
	$('.aaa').click(function(){
		console.log( $('select option:selected').length );
		$('select option:selected')[0].removeAttr('selected');
	})
</script>
